Method and machine for working metal



April 26, 1932. 1 w. HUGHES 5 METHOD AND MACHINE FOR WORKING METAL Filed Feb. 25, .192 6 Sheets-Sheet 1 I N VEN TOR:

B Y I A TTORNE Y.

April 26, 1932.

J. W. HUGHES METHOD AND MACHINE FOR WORKING METAL ATTORNEY.

April 26, 1932. 1 w. HUGHES 1,855,449

7 METHOD AND MACHINE FOR WORKING METAL Filed Feb. 25, 1927 6 Sheets-Sheet 3 1 N V EN TOR. Jfimeslfjf has;

A TTORNEY.

April 26, 1932.

J. W. HUGHES METHOD AND MACHINE FOR WORKING METAL Filed Feb. 25, 1927 6 Sheets-Sheet 4 I IN VEN TOR:

A TTORNE Y.

April 26, 1932. J. w. HUGHES METHOD AND MACHINE FOR WORKING METAL Filed Feb. 25, 1927 Sheets-Sheet 5 IN VENTOR.

A TTORNE Y.

April 26, 1932. J. w. HUGI- IES E[355,449

METHOD ANb MACBINE FOR WORKING ME TAL Filed Feb. 25, 1927 6 Sheets-She'et 6 INVENTOR: Jmes W'flykes ATTORNEY.

Patented Apr. 26, 1932 UNITED STATES PATENT oFFlcE JAMES W. HUGHES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO, BUDD' WHEEL COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYL- VANIA METHOD AND MACHINE FOR WORKING METAL Application filed February 25, 1927. Serial No. 170,893.

The present invention consists of an improved method of forming metal and apparatus for carrying out said method.

When an attempt is made to roll thin discs of large diameter and uniform thickness by means of a method and machine similar to those of Patent 915,232, granted March 16,

1909 to E. E. Slick, a phenomenon occurs which is easily understandable in the light of later experiments. It is evident if two elementary circles of an'unrolled disc be considered to undergo the same percentage of reduction by a rolling process, that the inner circle will suffer less elongation than the outer; and, since the radii of these elementary circles increase directly with their circumferences, that the outward movement of the inner ring will not be compatible with that of the outer ring. In fact, if rolling be continued long enough, there will be an actual separation of outer and inner portions of the disc under formation, indicating the generation of radial tensile stresses during rolling. Extending the principle to cover other forms of-discs: if there be a decrease in thickness toward the periphery of the desired disc section, it will be apparent that the situation is ag ravated since the elongation near the periphery will be even more than that produced in the rolling of a disc of uniform section.

It is an object of the present. invention to provide a remedy for these troubles by form ing metal outwardly from the center of the disc being rolled to neutralize these radial stresses and to provide throughout the section the mass of metal necessary to produce a perfect disc, even of tapered section.

Another object of the invention is to provide a method wherein the rolling pressure exerted during the rolling process is of a uniform and constant nature and is exerted in a predetermined relation to the rolling. Still another object of the invention is to provide a method and apparatus whereby various shapes, particularlv adapted to the formation of wheels and similar obiects, may be made rapidly. economically and of good quality.

The dies usedin the improved rolling mill to carry out the present invention are of composite formation, comprising central portions which serve not only to form but also to force metal from the center outwardly, and outer portions to give form to the outer parts of the rolled article. portions may act to effect the desired end by moving relatively to the outer portions, by special configuration or positioning, or by any other suitable arrangements.

The said dies are mounted on rotary die holders in such a way as to eliminate, to a large degree, the transfer of heat from the work and the dies to the machine, thus preserving the plasticity of the metal as much as possible. The die holders are rotated in unison and are adapted to be approached and separated under great pressure and to be rotated under that pressure. The apparatus by means of which the approach and separation movements of the dies is accomplished, produces a uniform and constant approach both before and during rolling.

The novel dies, die mountings and elements of the machine in which the method is carried out constitute other objects of the invention. The drawings illustrate a preferred form of the machine used in carrying out the.

method. They comprise:

Figure 1, a partly diagrammatic plan view of the complete machine;

Figure 2, a vertical section through Fig. 1 taken on the centers of the die holders;

Figures 3 and 4. horizontal sectional views through representative dies, showing the finished work in section;

Figures 5, 6, 7 and 8, similar diagrammatic groups, showing successive steps in forming various parts;

' Figure 9. a transverse section of the machine, showing the arrangement of the guide for the sliding head. and;

, Figure 10, an end View of the pump bat tery.

Figure 11, fragmentary longitudinal and transverse sections on an enlarged scale of the central portion of the dies during rolling.

The dies as generally shown in Figs. 1 and 2 in their relation to the machine and as more particularly shown in Fig. 3, comprise outer or main dies D, D and inner, central die portions (1, d by means of which the The said central center of the disc is kept under pressure during olling. The main dies D, D are insulateo thermally from their respective (lie holders 36, 37 by means of a layer or layers of asbestos or other suitable heat insulating material therebetween, as at L. The central dies (1, d are mounted on the ends of centrally-situated members of which one, 39, is reciprocable in its correspondingdie holder 361 In Fig. 3, one of the main dies D is substantially flat (except for the formative portions), while the other die d is of generally conical configuration the angle of the cone being the same as that by which the axes of the die holders deviate from alignment. In Fig. 4 only one central die d is shown and both main dies are conical, their combined angles being equal to that of their axial displacement. The dies of Fig. 3 are adapted to form an automotive hub and an integral disc which will subsequently be shaped into a brake drum or a wheel disc. The dies of Fig. 4 are designed to produce a disc having only a rudimentary hub for centering purposes. In the specific embodiment of Fig. 4 the main and auxiliary dies corresponding to D, D and d of Fig. 3 have been given the same general reference letter, but differentiated therefrom by the exponents. In both cases the structure shown is formed directly from a billet cut from a bar of substantially the diameter of the opening in which the central die d slides.

Referring to Figs. 1 and 2, it will be seen that die holders 36 and 37 are rotatably supported in movable and fixed heads M and F. respectively, said support being by means of suitable antifriction hearings to resist the heavy radial and thrust loadings imposed on the die holders. The die holders 36. 37. themselves are hollow, providing central apertures through which the members 38. 39 pass, providing support for the central dies d, d. The movable head M slides freely in asuitable guideway G provided in the base B (Fig. 9) toward and away from the fixed head F, and is operated in that manner by a plurality of hydraulic cylinders, 7 0, 71 together comprising means for either rapid or slow movements of approach and for separating the die heads after rolling.

In the preferred form of the invention the member 39 is mechanically connected with the movable head M in such a way as to move with approximately twice the velocity of the said head. The manner in which this is accomplished is shown more clearly in Fig. 2 in which the end of the movable head M opposite to the die D is hollowed out providing a space for gear to be described later. Closing the end of this hollow portion and secured to the head M in any suitable manner is an end" plate m which bears an enlarged sleeve 61 and a projecting lug 62. The enlarged sleeve 61 provides a slidi g bearing for a thrust bearing assembly, desig-' nated generally as 40, which comprises a palr of roller thrust bearings assembled in a hous- 'ing on either side of a thrust plate 63 which is fast on the end of the shaft 39. The lug 62 has journaled therein a connecting link 64 to which in turn is journaled a pair of links 52, only one of which is shown in Fig. 2. The links 52 occupy substantially a vertical position and are connected at their lower ends to the machine base B by means of an eye on the threaded retaining bolt 65. Adjusting nuts and lock nuts 55 are provided at each end of this retaining bolt on opposite sides of the portion of the base through which it passes. By means of these adjusting and lock nuts the amount of play between the retaining bolt 65 and the base B and the position of the pivotal point of the links 52 relative thereto, may be adjusted. The opposite ends of the links 52 have journaled thereon a thrust collar 66 which encircles a threaded shaft 67 bearing adjusting and lock nuts 53 similar to those carried by the retaining bolt 65 and having a similar function. The threaded shaft 67 comprises in effect a continuation of the central die bearing shaft 39 and contacts at its forward end with a plate 68 which is joined to the housing of the thrust bearing 40; its other end contacting slidingly in a guide bearing 69 formed in the yoke 42. It is apparent from the above description that the advance of the movable head M by its associated hydraulic cylinders 70, 71 will cause a similar advance of the central shaft 39 of approximately twice the speed of the advance of the former. The large resistances encountered by the die d, and the necessity for rotation of the die-bearing shaft 39 with the die D in which it is carried, demand a thrust bearing of large capacity as shown at 40. The provision of lost motion by the adjustment of the various adjusting and lock nuts 53-55 provides for the regulation of the degree of pressure exerted by the member 39 through the die (I upon the work and for the proper timing of this pressure during the Working cycle. A sliding detent 54 reciprocable in guides (not shown) upon the rear of the yoke 42 provides a means for operating the shaft 39 and its connected parts as an ejector to remove work from the face of the die D. This is brought about as follows. A lever 58 of general bell crank conformation is unbalanced by the weight 57. A connecting link pivoted to one of the arms of this lever 58 and to the detent 54 establishes an operative connection, the normal effect of which.

is to retain the detent in its elevated osition. A connecting rod 59 hearing ad usting nuts and lock nuts 56 provides means for actuating the lever by means of the movement of the head M. The portion of the connecting rod 59 between the nuts 56 is embraced by an eye on the rear of the head end plate m, the other end of the rod being pivoted to the second arm of the lever 58. By adjusting the nuts 56 the detent can be made operative at the desired point in the return stroke of the head M, blocking the rearward movement of the central shaft 39 so that the head M will recede therefrom and leave the work free of the die D. Further movement of the head M will cause contact of the eye which embraces the rod 59 with the rear set of the nuts 56, depressing the detent 54 through the operating linkage described above and freeing the shaft 39 for further rearward movement. Durin this latter stage the greater rapidity o motion of the central shaft 39 willwithdraw itwithin the die D preparing the dies for another operation on anew blank, and leaving the finished product free of the dies.

The hydraulic system is substantially conventional in nature, except that it is a closed system, using a battery of pumps P of a wellknown constant pressure type in which the volume of fluid delivered is independent of pressure generated in the system until a predetermined maximum is reached. The tank T in Fig. '1 serves only as a reservoir for an extra quantityof fluid and to keep the suction side of the system under a slight positive pressure, preventing the inward leakage of air, which is extremely undesirable. In operation, this s stem gives the advance of the movable hea acter until the pressure reaches the predetermined character, whereupon the volume of fluid delivered will be automatically limited to the amount necessary to maintain the maximum pressure chosen. As a result of this characteristicly uniform feed the product is smooth and free from buckles or waves. The uniformity of advance of the head M with relation to the progress of the rolling is due to the use of substantially constant speed drive motors in the present instance, the motors driving the pump battery P and the dies D, I) being of that nature. Due to the nice speed regulation obtained in synchronous and induction-type motors, as now built, the eifect is the same as if but one motor were used for all the elements of the machine.

The two die holders are driven by a suitable motor 21, through a system of reduction gears 22 (which includes a flywheel to promote steadiness of motion) an electrically controlled clutch 23, and a line shaft 25.

' The said line shaft is made up of sections 26, 27 and 28 universally jointed at 32,32 and suitably journalled in the machine base 13. A brake 24 is provided on the first named section 26, which also bears a gear 29. The gear 29 drives the die-holder 37 through gears 30 and 31, carried by the head and die holder respectively while die holder 36 in-the mova steady uniform charable head is driven from shaft section 28 through a wide-faced gear 33 and gears 34, 35, carried by the head M and a holder 36 respectively, thus allowing reciprocation of the head M. The middle section 27 of the shaft 25 may be parted, driving connection being established through a suitable form of powerful friction coupling C which will permit slippage on occasion to equalize the power between the two die holders.

The preferred form of machine disclosed is adapted for what might be called semiautomatic action; that is, the machine fin ishes a billet under automatic control, but requires external guidance in the loading, starting and unloading steps. As shown in Fig. 1, this'control is arranged in the form of line shafts 10. and 11, on opposite sides of the machine base, connected by a shaft 16 and angle couplings or bevel gear units 14, 15. A motor 12 drives these control shafts through a reduction gear 13. The motor is arranged to operate the shafts 10, 11 through one working cycle, as described later, and

then to stop; or the cycle of operation may be arranged to give a suflicient pause between rollings to afford time for unloading and loading without shut-down. In any event, the line shaft 10, 11 controls the operation of the brake 24 through a cam 17 driven by shaft 10, and operating link 17 connecting the cam and the movable member of the brake and the operation of hydraulic relay valves 4;, '0' through cams 19 driven by shaft 11 and connected with the relayvalves by suitable connections, such as a system of links and levers. The brake 24 is released on starting and applied at the end of the working cycle. The valve '11 controls the master valves V on the main cylinders 70, acting as a relay in moving the large, heavy valves V required to control the large volume of flow to and from the main cylinders 70. The other valve '0' directly controls the pull-back cylinders 71, which efiect rapid movements of the head M to and from its operative position, and add to the pressure produced during operation of the main cylinders 70. Suitable header pipes 45, 46 conduct the fluid between the valves 0, v and the pum battery P, while a large diameter pipe 4? acts as an equalizing connection and exhaust main for the cylinders 70, connecting the tank T and the pumps D into a circuit under a slight gravity head. The clutch 23 is of hub without a disc. Similarly, Figs. 5 and 6 show alternative steps in the formation of a disc without a hub somewhat similar to that shown in Fig. 4 in completed form. In Fig. 3 the ends of the die holders 3637 are shown hollowed out to provide concentric seating surfaces which serve as seats for the dies D and D which are further secured by suitable bolts or any other device or devices. A layer or several layers of insulating substance L such as asbestos, magnesia or any suitable refractory pressure resisting means is shown serving to cut down the transfer of heat from the dies to the die holders 3637. The abutting faces D-D have removable wearing faces at their exterior peripheries and at their central portions. These permit the renewal of the portions of the dies as at d" which are more subject to wear or permit the use of a die body of cheaper metal than if the whole die were constructed of the same highly resistant metal. The two central die members (Zcl' are threaded into central shafts 3839 and as shown in Fig. 2 may be connected through the agency of an intermediate spacer block which in turn is threaded directly to the central member.

In Fig. 4 the structure is very similar except that the use of dies DD' of somewhat different contours requires the provision of an adaptor member to join these dies with the die holders 36 and 37. Between the' engaging surfaces of the dies D-D, the adapters and the die holders are layers of heat insulating composition L such as were described in connection with Fig. 3. The function of these heat insulating layers is twofold, serving not only to keep the temperature of the bearings of the machine from reaching a dangerous point during working of hot metal, but also to keep the dies at the most favorable temperature for work. Without the insulation the conduction of heat to the large masses of metal in the die holders 36- 37, the heads M and F, and the large body of lubricating oil necessary for the bearings would be so rapid as to prevent the attainment of the desired time'or degree of working because of too rapid chilling of the metal.

The illustrations of successive steps in the formation of various products of this machine given in Figs. 5 to 8 is purely diagrammatic, only the principal contours of the various die surfaces being shown. Although the form of certain of the dies in these diarammatic views are shown to vary slightly from those shown in Fig. 1, 2 and 3, the same general reference characters are used as in those figures, to designate corresponding dies. In Fig. 5 there is shown in the first view, I, the placing of a billet W between two dies. One die D of substantially conical formation is carried in the fixed head F. The other die D of substantially plane formation is carried in the movable head M, the conical die being shown on the left in the figure, the plane die being shown on the right. A similar arrangement is followed in the other views. The die D in Fig. 5 has at its center an auxiliary die 65 corresponding to that shown in Fig. 3. Since the apex of the conical surface of the die D lies in the axis of the die D, it is apparent that the die d is eccentric with relation to the axis of the said.

die D. The die (if consists of a cylindrical block having a plane face. and a central hemispherical concavity mounted on the end 0; the central plunger 39 as shown in the other view. The billet W, in this case, has a depression at one end to engage the die dand a projection at the other end to engage the hollow in the die d. As shown in the first stage of Fig. 5, the billet has just been loaded into the machine and pressure has not as yet been applied. In the second view, II, of Fig. 5, the dies D-D have been brought together under great pressure and the die d has been advanced a small extent. The metal of the billet has suffered considerable expansion, bulging out in all directions centrally between the dies, and also crowding back into the central concavity of the die D to meet the advancing auxiliary die d. The curvature or bulging'of the billet between the dies serves to free the exterior surface to a great degree of the scale formed thereon during heating. In the third view III of Fig. 5, the pressing has been completed and rolling has just been initiated with the result that the billet has assumed a substantially disc-like shape of considerable thickness and that the central die (1 has started to force the metal from the central concavity of the die D outward between the dies, there being no other place for it to go. The auxiliary die (1 has also, due to its eccentricity, started to force metal from the center of the billet outward since it moves, during rotation of the dies in a much greater space than it occupies at any given moment as shown in this view and in the succeeding view IV. The operation is concluded in the fourth view IV of Fig. 5, where the disc has reached its maximum attenuation and practically all of the central material except that required to center the disc has been forced out into the bod of the disc by the eccentric movement of the die d with respect to the die D, and by the movement of the plunger bearing die The associated views which comprise Fig. 6 are substantially similar to those of Fig. 5 except that the use of the reciprocable auxiliary die d is omitted, there being some instances, where a great degree of reduction is not desired, when this can be done. The action of the auxiliary die d in Fig. 6 dislaces sufiicient metal from the center of the lank to produce a perfect disc without the aid of a central plunger. The first two views I and II of this figure comprise, as described above, the operations of loading and of pressing, the billet being of substantially identical shape. In the third view III ofthis figure, rolling has been initiated with the result that the auxiliary die (1' begins to press the metal away from "the center forcingit towards the outer portions of the disc, the die (1 rolling around the periphery of this constantly-deepening cavity which it forms as the rolling proceeds and as the dies D, D approach each other. With continued rolling and pressing this action continues, maintaining a supply of metal in all parts of the disc sufficient to prevent the formationof destructive radial strains, producing a finished disc similar to that of Fig. 5 with only enough metal at the hub to center the disc.

Fig. 7 comprises only three views, the formation of a hub alone being shown. In this case the action of the auxiliary; dies dd is more for the purpose of coring out the greater portion of the center of the billet, thus lightening the labor of machinin of the hub, than to provide for the outwar feeding of metal. As shown in the first view I, the cylindrical billet with'one end preformed to engage the die d is placed between the dies, one end being of substantially the size of the central opening in the die D. The second view II, of Fig. 7, shows the completion of the pressing operation before rollin has be gun. The greater portion of the wor of formation has been completed during the pressing, the billet being extruded outwardly a great extent and the auxiliary dies having substantially completed the central piercing of the hub. Finally, on the beginning of rolling, the metal is spread outward still further filling the smaller details of the die contours and completing the form as shown in the third view III of Fig. 7. Here again, the effect of the auxiliary die d can be seen in displacing a greater volume of metal than it itself possesses.

Fig. 8 shows four successive stages I, II, III and IV of rolling a hub very similar to that of Fig. 7 but which has a disc formed integrally therewith. The billet in this case, as shown in the first view I, is of correspondingly greater size requiring greater separation of the dies at the loading point. In the second View II the dies have been brought together upon the billet partly extruding it outward between the dies and partly forcing it backward into the central aperture ofdie D meeting the advancing auxiliary die d. The third view III shows' the beginnin of rolling in which the continued advance 0 the auxiliary die at and the wobbling action of the auxiliary die (1 have initiated the outward feeding of metal to form the disc. Continued rolling and advance of the die (Z produces the form shown in the fourth and last View IV in which the disc is completed and the hub pierced practically throughout. A. structure of this nature is intended to be formed into a wheel by the addition of a tire-carrying rim, or into a brake drum by cupping, in both cases the finished structure has an integral hub in permanent alinement with the disc portion. The economy of such a product is immediately apparent when the large number of proposals for demountable rims and wheels, and the usual complexity of such plans are considered.

Figure 11 shows, to a larger scale, the action of the auxiliary die 03', in dies of a nature similar to those of Fig. 6. In Figure 11, rolling has become substantially complete, the blank Whaving assumed an attenuated disc-like form. The auxiliary die d, as shown most clearly, rolls around the axis of the die D, much as apinion rolls in the interior of a ring gear. As a result of this action, and since the greater portion of the auxiliary die df is eccentric to the axis of the die D, a cavity 0 is worked out at the center of the blank, the displaced metal being forced outwardly to supply the metal needed to form the disc.

The yoke 42 which supports the hydraulic cylinders 70, 71, with appurtenant elements provides a simple arrangement for limiting the approach of the head M to the head F, and thus, for limiting the amount of work done on the blank. As shown in Figures l and 9, the yoke 42 is secured to the end of the machine base B by means of large bolts 49 having suitable securing and locking bolts for this purpose. The bolts 49 pass through alined apertures in the yoke 42 and the base B, the said nuts drawing the parts together and securing them in that position. The bolts 49 extend beyond this point on each side of the head M, ending in a threadedportion adjacent the middle of the head, which portion bears other lock or jamb nuts 50 at each side of the head M. A pair of arms 51 extend laterally from the said head and fit partially around the said bolts, as shown in Figure 9. Contact of the arms 51 with the lock nuts 50 thus limits the forward travel of the head M. The threaded connection of these nuts with the bolts 49 provides for ready adjustment. Another adjustment providing for variations in the relative angular positions of the heads is provided by the bolted connection of head F with the base B, as shown in Figure 1. The bolts are not apparatus as described in the preceding specification, carries out the method of the invention by means of two specific structural arrangements; by the use of an auxiliary movable element capable ofexerting pressure on the center of the blank independently of the pressure elsewhere and by the use of a central element of a die,so related thereto as to displace more than its own volume of metal during operation. A third manner of practicing the method of the invention consists in combining these two aforesaid structural arrangements. The improved method embraces all of these and other variations and should not be limited thereby, but only by the scope of the appended claims.

1. A method of working metal comprising rolling a blank between opposed rotary dies, and simultaneously forcing metal outwardly from the center of said blank to supply metal between said dies additionally to that forced outwardly by the rolling pressure.

2. A method of working metal comprising the application of rolling pressure on successive radii of a blank while independently and simultaneously maintaining pressure at the center of the said blank, whereby to force metal outwardly from the center independently of the flow caused by the rolling pressure.

3. A method of working metal comprising the axial compression of a billet cut from a bar and the end surface rolling of said billet, while maintaining pressure on the central portions of the billet independently of said compression, whereby to force metal outwardly from the center independently of the flow caused by the rolling pressure.

4. A method of working metal comprising simultaneous axial compression and end surface rolling while maintaining a predetermined time relation between said compression and said rolling.

5. A method of working metal comprising-rolling a blank between opposed dies to reduce its axial thickness and simultaneous- 1y causing a forcible axial approach of said dies in synchronism with said rolling.

6. A method of working metal comprising the provision of fixed and movable dies, inserting a billet therebetween, rotating said dies and causing a relative approach thereof in predetermined time relation to said rotation.

7 A methodtof working metal comprising rolling a billet between relatively movable dies, causing such relative movement in a predetermined time relation to said rolling and subjecting the central portion of said billet to pressure of a different orderof magnitude from the pressure of rolling.

8. A method of forming metal consisting in pressing a blank between rotatable die faces having their axes out of alignment, setting said dies in rotation, and applying additioning said billet by pressure on the ends thereof, and completely forming said billet by applying a rolling pressure to the said end surfaces and maintaining the pressure of said rolling substantially constant during the progress of the rolling action.v

11. Apparatus for working metal comprising substantially rotary dies and suitable supporting members, said dies being insulated thermally from said supporting members.

li Apparatus of the character described comprising rotatable dies on relatively angularly adjustable axes having relative approach and separation movements and common drive means for rotating both of said dies including a universally jointed, sectional shaft.

13. Apparatus of the character described comprising heads having angularly adjustable axes supporting cooperating rotatable dies and common driving means for rotating said dies, said driving means being independent of the angular adjustment of said axes.

14. Apparatus of the character described comprising coacting rotatable dies, means for effecting I'QlfifiXQ approach and separation of said dies and controlling means relating said approach and separation to said rotation in a predetermined manner.

15. Apparatus of the character described comprising dies having movements of rotation and of relative approach and separation, means including a cam shaft for controlling said approach and separation movements in a predetermined relation to said rotation, said ineans also including devices for controlling said rotation.

16. Apparatus of the character described comprising a centrally perforated rolling die, an auxiliary die in said central perforation and means for causing a longitudinal movement of said auxiliary die relative to said first named die.

17. Apparatus of the character described comprising relatively movable rolling dies. an auxiliary die concentric with one of said dies and movable relative thereto during said relative movement of the first named dies to feed metal from a blank outwardly between the rolling dies.

emme 18. Apparatus of the character described comprising relatively movable rolling dies, an auxiliary die carried centrally of a movable die and means temporarily connecting said auxiliary die to relatively fixed machine parts to produce movements of said auxiliary die relative to the die in which it is carried to feed metal from a blank outwardly between the rolling dies.

19. Apparatus of thecharacter described comprising a die having a face of substantially conical configuration, having an auxiliary central metal feeding portion projecting beyond the apex of the cone which defines said face.

20. A method of forging a metal blank which comprises extruding the metal of the blank laterally and simultaneously forcing metal outwardly from the central portion thereof to replace-a portion of the extruded metal independently of said first-named extruding action.

21. Apparatus for working metal comprising a forging die, a supporting member for said forgin die, and an insulating member interposed ietween said forging die and the supporting member.

22. Apparatus of the character described comprising a pair of relatively movable extruding dies, one of said dies having an auxiliary central projection adapted to feed metal outwardly to replace a portion of the extruded metal.

23. Apparatus of the character described 5 comprising a pair of relatively rotatable dies arranged at an obtuse angle to each other, one of said dies having a substantially conical face, and a metal feeding projection extending beyond the apex of said conical face.

24. Apparatus of the character described comprising relatively movable rolling dies, an auxiliary die concentric with a movable die of said relatively movable group of dies and movable relative thereto during said rel- 46 ative movement of the dies to feed metal from a blank outwardly between the dies.

25. The method of rolling relatively thin wheel discs which consists in first forging a relatively thick disc with a hub, centering l0 and holding the disc for rolling by means of said hub, rolling the disc to thin the same, during rolling feeding metal from the hub to supply metal to the disc body as it is rolled.

B5 26. The method of forging a metal blank which comprises effecting an extrusion of the metal of the outer peripheral regions of the blank by a rolling process and forcing metal radially outwardly from the central port-ion 00 of the blank during the extruding operation.

In testimony whereof he hereunto afiixes his signature.

JAMES W. HUGHES. 

